Traditional power conversion adopts the pulse width modulation (PWM) technique, the circuit is complex and difficult to adjust, all power devices work at high-frequency range, an intense EMI interference is generated, so that the sine wave voltage output by the power grid is seriously distorted, and the intense EMI interference is the greatest pollution source to the power grid. If there is no traditional power converter, and the power grid world is a blue sky. Besides the investment or disconnection of electric equipment, there is no other pollution source any more.
The whole input power by traditional power conversion must be subject to power conversion before becoming an output power. The whole converted power must pass through a magnetic core transformer to reach the output end. The input power is subject to traditional power conversion, which means more investment and payment on cost, size, weight and power consumption of the equipment. The converted power passes through the magnetic core transformer, which means the loss in electric power.
The complete efficiency of the traditional power converter is about 85%, and the power factor (PFC) is about 60%. A low efficiency is the inevitable result of traditional power conversion, and a low power factor means the severity of pollution. Facts illustrate the traditional power converter has large power consumption and low efficiency and is unfriendly to environment and is unsafe.